Please I am about to buy a new corsair one i60 PC, and it has this storage : 480GB M.2 NVMe SSD && 2TB 5400RPM 2.5” HDD all packed in a Z370 Mini-ITX motherboard, I am wondering if I can replace its HDD with a Samsung evo 970 SSD???
You can replace the HDD with a sata based 860 evo drive if you wish.
The performance difference will be great compared to a 5400 rpm HDD.
But you will see very little difference in performance vs. a nvme drive.
You could also consider changing out the 480gb nvme m.2 device to a 970 evo of up to 2tb, accomplishing most of what you originally proposed.
To do that easily, you would use the Samsung ssd migration app to move your windows C drive to the larger drive.
You can do this by attaching the larger drive to a usb tp pcie adapter cable for the copy.